<wicket:extend>

    <form wicket:id="form">

        <label for="username">
            Username
        </label>
        <input id="username" placeholder="username" type="text" wicket:id="userName"/>

        <label for="password">
            Password
        </label>
        <input id="password" placeholder="password" type="password" wicket:id="password"/>

        <button wicket:id="login" href="#">
            <span>login</span>
        </button>
    </form>
</wicket:extend>